This invention relates to integrated circuitry, to methods of fabricating integrated circuitry, to methods of forming local interconnects, and to methods of forming conductive lines.
The reduction in memory cell and other circuit size implemented in high density dynamic random access memories (DRAMs) and other circuitry is a continuing goal in semiconductor fabrication. Implementing electric circuits involves connecting isolated devices through specific electric paths. When fabricating silicon and other semiconductive materials into integrated circuits, conductive devices built into semiconductive substrates need to be isolated from one another. Such isolation typically occurs in the form of either trench and refill field isolation regions or LOCOS grown field oxide.
Conductive lines, for example transistor gate lines, are formed over bulk semiconductor substrates. Some lines run globally over large areas of the semiconductor substrate. Others are much shorter and associated with very small portions of the integrated circuitry. This invention was principally motivated in making processing and structure improvements involving local interconnects, although the invention is not so limited.
The invention includes integrated circuitry, methods of fabricating integrated circuitry, methods of forming local interconnects, and methods of forming conductive lines. In one implementation, a method of fabricating integrated circuitry comprises forming a conductive line having opposing sidewalls over a semiconductor substrate. An insulating layer is deposited over the substrate and the line. The insulating layer is etched proximate the line along at least a portion of at least one sidewall of the line. After the etching, an insulating spacer forming layer is deposited over the substrate and the line, and it is anisotropically etched to form an insulating sidewall spacer along said portion of the at least one sidewall.
In one implementation, a method of forming a local interconnect comprises forming at least two transistor gates over a semiconductor substrate. A local interconnect layer is deposited to overlie at least one of the transistor gates and interconnect at least one source/drain region of one of the gates with semiconductor substrate material proximate another of the transistor gates. In one aspect, a conductivity enhancing impurity is implanted into the local interconnect layer in at least two implanting steps, with one of the two implantings providing a peak implant location which is deeper into the layer than the other. Conductivity enhancing impurity is diffused from the local interconnect layer into semiconductor substrate material therebeneath. In one aspect, a conductivity enhancing impurity is implanted through the local interconnect layer into semiconductor substrate material therebeneath. In one implementation, field isolation material regions and active area regions are formed on a semiconductor substrate. A trench is etched into the field isolation material into a desired line configuration. A conductive material is deposited to at least partially fill the trench and form a conductive line therein.
In one implementation, integrated circuitry comprises a semiconductor substrate comprising field isolation material regions and active area regions. A conductive line is received within a trench formed within the field isolation material.
Other implementations are disclosed, contemplated and claimed in accordance with the invention.